Development of the Technique of Quantitative Determination of Antracene derivatives in roots of Rheum officinale

 

Semeniuta Ksenia Nikolaevna¹, Kurkin Vladimir Alexandrovich²,

Shmygareva Anna Anatolyevna¹, Sankov Anatoly Nikolayevich¹

¹Department of Economics of Pharmacy, Pharmaceutical Technology and Pharmacognosy, Orenburg State Medical University, Orenburg Oblast, Russia

²Department of Pharmacognosy, Botany and Phytotherapy, Samara State Medical University, Samara Oblast, Russia

 

ABSTRACT:

This paper discusses the current aspects of improvement of methods of standardization of roots of Rheum officinale. The new approaches are proposed for the quantitative analysis of the content of anthracene derivatives of roots of Rheum officinale, which consists in the using of the method of spectrophotometry at analytical wavelength of 510 nm calculated on Frangula-emodin and the use of ultrasound for the maximum yield of anthracene derivatives of raw materials and reducing the time of extraction in a water bath. The existing method for the determination of anthracene derivatives in the roots of Rheum palmatum presented in the State Pharmacopoeia of the Russian Federation, XIV edition, provides for a long extraction in a water bath. The use of physical factors, such as ultrasound, increases the yield of biologically active substances in the extraction due to the destruction of the cell structure, which reduces the extraction time.

 

 

INTRODUCTION:

The role of medicinal plants and derived from them effective drugs and dosage forms has increased significantly in recent years. The scope of scientific research is expanding, both in the field of research of new medicinal plants, and more in-depth study of the chemical composition of plants that have long been used in scientific and folk medicine [1]. Rheum officinale (family Polygonaceae) is a medicinal plant widely used in traditional medicine of the countries of the European Union, great Britain, Japan, and Chinese medicine is promising for use in domestic medicine, along with the Rheum palmatum in view of the close relationship of these species of rhubarb. The roots of Rheum officinale contain a large amount of anthracene derivatives and tannins, which is also characteristic of the roots of Rheum palmatum [2,3].

 

 

The method of quantitative determination of anthracene derivatives in Rheum officinale roots was taken as a basis for the methodology of quantitative determination of anthracene derivatives in roots by the Rheum palmatum spectrophotometric method in terms of Frangula-emodin, which provides for the extraction of crushed Rheum palmatum roots in a boiling water bath for 60 minutes at a ratio of "raw-extractant" - 1:50 to 70% ethyl alcohol, described in the FS.2.5.0092.18 State Pharmacopoeia of the Russian Federation XIV edition [4]. In order to optimize this technique, the optimal concentration of ethyl alcohol was chosen for the roots of Rheum officinale - 60%; to reduce the extraction time in a boiling water bath, the technique introduced the effect of ultrasound as a physical factor that increases the completeness and speed of extraction of biologically active substances due to the destruction of membranes of plant cells [5,6], which ultimately allowed to achieve high concentrations (about 2,8%) of anthracene derivatives in extraction and significantly reduce the time of the study.

 

The aim of the study was to develop methods to quantify the amount anthracenedione in the roots of Rheum officinale.

MATERIAL AND METHODS OF RESEARCH:

The objects of the study were the roots of Rheum officinale LLC "World of Herbs" (Ukraine, Kharkiv, 2018). Electronic spectra were measured on the Unico 2800 UV spectrophotometer.

 

Method of determination. The analytical sample of raw materials is ground to the size of particles passing through a sieve with holes 1 mm in diameter. About 1 g of crushed raw materials (exact sample) is placed in a flask with a 100 ml capacity, 100 ml, 60% ethyl alcohol is added. The flask is closed with a stopper, weighed to within ±0,01, attached to the reverse refrigerator and heated in a boiling water bath (moderate boiling) for 30 minutes. Then, within 15 minutes, the extraction is carried out under the influence of ultrasound, after which the missing extractant is weighed and replenished to the initial mass. Extraction is filtered through a paper filter ("red" strip). The tested solution is prepared as follows: 1 ml of the resulting extraction is placed in a volumetric flask with a capacity of 50 ml and the volume of the solution is adjusted to the mark with an alkaline ammonia solution prepared in accordance with the requirements of the State Pharmacopoeia of the Russian Federation XIV edition. After cooling, the optical density is measured on a spectrophotometer at a wavelength of 510 nm. As a comparison solution, a solution obtained as follows is used: 1 ml of extraction is placed in a volumetric flask with a capacity of 50 ml and the volume of the solution is adjusted with water to the mark. The content of the amount of anthracene derivatives is carried out according to the formula

 

                 Ax 100x 50 x 100

X= ---------------------------------------

              A^1% _1cm  x 1 x a x (100-W)

 

Where A is the optical density of the tested solution;

– specific absorption rate of CO Frangula-emodin at a wavelength of 510 nm, equal to 465;

100 – extractant volume, ml;

50 – volume of solution A, ml;

1 – volume of aliquots of solution A, ml;

a – linkage of raw materials, g;

W – moisture content of raw materials, %.

 

Metrological characteristics of the method of quantitative determination of the amount of anthracene derivatives in Rheum officinale roots are presented in table 2. The results of statistical processing of the experiments indicate that the error of a single determination of the amount of anthracene derivatives in the roots of rhubarb drug is ±4,50.

 

 

The results of the study and their discussion:

The roots of Rheum officinale contain a large number anthracene derivatives, which are dominated by Frangula-emodin, Rheum-emodin, and rein chrysophanol [1,2,7]. UV spectra of solutions of water-alcohol extracts from raw materials were studied using the Unico 2800 spectrophotometer. In our opinion, the use of Frangula-emodin, which gives a maximum absorption at a wavelength of about 510 nm (Fig. 1) as standard is optimal. Extraction was carried out at different ratios of "raw-extractant", and the extraction time in a water bath and the effect of ultrasound varied (table.1). When modifying the method of quantitative determination of the amount of anthracene derivatives in the Rheum officinale  roots drug identified optimal conditions for the extraction of anthracene derivatives: extractant – 60% ethyl alcohol; ratio "raw – extractant" -1:100; extraction time – 30 minutes in a water bath at a temperature of 80-90 °C, 15 minutes of extraction under the influence of ultrasound (Fig. 2). To control the amount of anthracene derivatives was determined by the previously proposed extraction method for 30 minutes in a water bath.

 

 

Figure 1: The electronic spectrum of alkali-ammonium solution of Frangula-emodin

 

Figure 2: Electronic spectra of the initial solution (1) and alkaline-ammonia solution (2) of water-alcohol extraction from roots of Rheum officinale

Table 1: The influence of various factors on the completeness of the extraction of anthracene derivatives from the roots of Rheum officinale

Extractant - ethyl alcohol concentration, %	Ratio "raw material:extractant"	extraction time, min	ULTRASONIC, min	Optical density	% content of anthracenederivatives in terms of Frangula-emodin
40%	1:50	90	-	0,3148	1,92572896
			15	0,3120	1,90860106
50%	1:50	90	-	0,3524	2,15659372
			15	0,3546	2,17005713
60%	1:50	90	-	0,3958	2,38301596
			15	0,4193	2,52450376
70%	1:50	90	-	0,3984	2,40805439
			15	0,3332	2,01396517
80%	1:50	90	-	0,3354	2,05073052
			15	0,3560	2,17668475
95%	1:50	90	-	0,3121	1,90431102
			15	0,2820	1,7206527
60%	1:50	60	-	0,2960	1,80233809
			15	0,2863	1,74324798
60%	1:50	30	-	0,2799	1,71121851
			15	0,3032	1,8536665
60%	1:25	90	-	0,6219	1,90670721
			15	0,5669	1,73808059
60%	1:100	90	-	0,2103	2,58496696
			15	0,2175	2,67346797
60%	1:100	60	-	0,2180	2,66846761
			15	0,2125	2,60114389
60%	1:100	30	-	0,2177	2,69874015
			15	0,2255	2,79543364
60%	1:100	15	-	0,2141	2,59223163
			15	0,2215	2,68182768

 

Table 2. Metrological characteristics of the method of quantitative determination of the amount of anthracene derivatives in the raw material of Rheum officinale

f		S	P, %	t (P,f)	DX	E, %
10	2,70	0,05477	95	2,23	±0,122	±4,50

 

CONCLUSION:

A modification of the spectrophotometric method of quantitative determination of the amount of anthracene derivatives in the roots of Rheum officinale with using ultrasound extraction was developed. The content of the amount of anthracene derivatives in the raw material equal to 2.80% is achieved by a combination of extraction in a water bath and ultrasound extraction. This technique allows to obtain a high content of anthracene derivatives, reduce the extraction time in a water bath and can be used to extract anthracene derivatives from other types of medicinal plant raw materials.

 

REFERENCES:

1.      Murav’eva D.A., Samylina I.А., Yakovlev G.P., Pharmacognosy. Moscow; 2002, 152-155.

2.      Kurkin V.A. Pharmacognosy: textbook for students of pharmaceutical faculties, Edn 2, Samara, 2007; 828-840

3.      Kurkin V.A. Fundamentals of Phytotherapy: textbook for students of pharmaceutical universities. Samara:  OOO “Ofort”: GOU VPO “Sam GMU Roszdrava”; 2009.

4.      State Pharmacopeia of Russian Federation. 14 Edition. Volume 2. Pharmaceutical article 2.5.0092.18 “Radix rhei”, Moscow; 2018 Russian Federation; 2018

5.      Molchanov G.Y. Ultrasonic in pharmacy. Мoscow, Меdicine; 1980.

6.      Bruk M.M. Obtaining medicines from plant and animal raw materials under the influence of ultrasound. In the book. Ultrasound in physiology and medicine. Vol. 1, Rostov-on-don; 1972, 115-116.

7.      Kurkin V.A., Shmygareva A.A., Sankov A.N. Anthracene derivatives of Pharmacopoeia plants: monograph / Samara: OOO “Ofort”: GOU VPO “Sam GMU Roszdrava”; 2016.

 

 

 

 

 

 

Received on 12.04.2019           Modified on 10.05.2019

Accepted on 23.05.2019         © RJPT All right reserved